Making spiral welded pipe



Aug. 26, 1930. A. J. HAND 1,774,000

IAKING SPIRAL wELDED PUE Filed Oct. 18. 1927 INVENTOR. BJY QM; .UQ c( Patented Aug. 26, 1930 A UNITED STATES PATENT OFFICE AUGUSTIN J'. HAND, OF BERKELEY, CALIFORNIA, ASSIGNOR TO CALIFORNIA CORRU- GATED CULV'EBT COMPANY, OF BERKELEY, CALIFORNIA, A CORPORATION OF CALL,

i IOBNIA Application led October 18, 1927. Serial No. 226,879.

The present invention relates to the art of making spiral welded metallic pipe, anl has for its principal object the rovision of a welded seam, of greater thic ness than the adjacent metal, which can be simply and rapidly made Without the addition of extra metal from an outside source.

This object is achieved, broadly, by crowding the edges of the joint together so forcibly that they have a tendency either to be upset or to over-lap. The result is that when said ed es are rendered plastic or fluidic by the welding heat, instead of actuallyover-lapping or bein upset, the pressure forces them together to orm a perfect weld, of greater thickness than the body of the pipe. Such a thickened weld is of advantage in insuring a strength at least e ual to that of the surroundin met-al, and a so in providing a helical reinorcing rib for the pipe..

By this means, moreover, I am able to use a lower degree of heat than is possible in makinga pure fusion weld in the absence of pressure, and at the same time to produce a more even and perfect weld, without the necessity for such accurate control of tem erat-ure as is necessary in the fusion wel It is entirely7 possible, however, to make a fusion Weld, if such be desired, with the same thickened effect. I am also able to use a gas flame, since no extra metal is needed, such as is sometimes supplied by an electric arc from a metallic electrode.

My invention will be more completely described in the following specifcatiaon, which should be read with the understanding that the form, construction, arrangement, and use of the several parts may be varied, within the limits of the a pended claims, without departing from t e spirit of the invention as set forth in said clalms.

Reference should be had to the accompanying drawings, wherein 'Fig 1 is a partly diagrammatic plan view of a simple form of apparatus for carrying out the invention.

Fi 2 is a dia rammatic section taken on the line 2-2 of ig. 1 and enlarged.

Fig. 3 is an end elevation, enlarged, of the pipe guiding means shown in Fig. 1.

Fig. 4 is a transverse section of the meeting edges of the helically wound sheet, showing the relative positions they would assume if no i heat were applied.

Fig. 5 is a similar section of the completed weld, showing the effect of the welding heat and the ressure produced by the over-lapping ten ency.

In the drawings, the reference numeral 1 designates the sheet of metal which is wound helically into tubular form to make the pipe 2. Inasmuch as any suitable means may be employed for the winding operation, I have merely indicated, in Figs. 1 and 2, three rollers 3, 4, and 5, the roller 3 lying inside the pipe and the rollers 4 and 5 being outside and acting to bend the sheetj, over said roller 3. guide rollers 6 are also indicated to guide the sheet 1 into the bending rollers 3, 4, and 5 at the proper angle. Any suitable means, not

shown, ma be employed for feeding the sheet l forward and causing it to pass/between the bending rollers 3, 4, and 5.

The bending and guide rollers are so positioned, with respect to the width of the sheet, that the rear edge 1 of said sheet would normally come into abutting relation with the forward edge l" at the point A, at which point the two edges are welded together, the pipe 2 coming endwise off the ending rollers 3, 4, and 5 in its completed form.

I provide means for supporting and guiding the pipe 2 as it leaves the bending and welding mechanism, and said means is best formed upon a base 7, Fig. 1, adapted for horizontal swinging movement about a pivot 8 in approximate vertical alignment beneath the welding point A. A triangular frame 9 is mounted upon the base 7, and carries rollers 10, Fig. 3, adapted to Contact with the pipe. The rollers 10 are best mounted in swivel ofiset brackets 11, so that they track upon the pipe after the manner of casters. One of said caster rollers is preferably mounted in an adjustable bracket 12, which may be moved up or down in one leg of the frame 9 by a screw indicated at 13, so that different sizes of pipe can be accommodated. The base 7 rests upon an arcuate rail 14, Fig. 1, and some suitable device, such as s screw and nut mechanism indicated at 15, is provided for moving said base and its pipe guide horizontally about its pivot 8.

It the pipe 2 were allowed to discharge -freely from the bending rollers 5, d, and 5, its anis would be parallel with the axes of said rollers, and it would lie in the position indicated in dotted lines in Fig. l. The essential 'feature ot' my invention, however, resides in oiilsetting the pipe, preferably toward the right as Viewed in Fig. I, as indicated, in some exaggeration, by the full line position, this being accomplished by shifting the guide base Y to the right by means of its screw l5.

rthis otisetting ot the pipe causes the meeting edges ln and lb ot the sheet to be crowded together with suiicient force to produce a tendency toward eier-lapping, as shown in Li, but, since the metal is rendered plastic the Welding heat applied at this point,

pressure produced by the bending reet over the roller 3 causes the edges to forni a perfect Weld of greater than that et the sheet l, as shown in Fig. ii, Lie lr Ide et the eine being almost smooth. and ti ickened r I ing a l result, ri duced v Lttinc qe. rIlle same can be pro- -ting edges into Wding them toby the inished -ion oi' y as to cause ne point er Weiding. no nie; be employed for the sheet in '.netal required is all derived l, 4'here is no nec s ntiolial metal, and I ern tnererore able to use e eas torch, as indicated IG s. 2 and o. Moreover, the pressure pl to the meeting edges by the otsetting of the pipe Q @nab es nieto malte e perfect Weld Without heating the metal to timid condition; in other words, I can malte s pressure Weld rather than a fusion weld, with consequently less danger ot imperfections. IfIongerer, a fusion weld may bc made it desired,-vith the saine thickened result, tie pressure oi the meeting edges causing in, Twhen fused, to torni Weld or seam of eter tliiclrneiss than of the sheet.

In the manufacture el spiral Welded e, the method of forming e Welded seam greater in thickness than the adjacent metel, which consists in Winding a sheet of metal helically into tubular torni with its edges in abutting relation, heating' the meeting edges of the Windingl sheet to welding temperature, and crowding said heated edges together, by odsetting the ileished portion o the pipe with.

'and heating said respect to the axis of Winding, to cause them AUGUSTIN J. HAND.

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